text: //chapter 3 recursion
  
  var isEven = function (number) {
  
      if(number==0) {
        return true;
      }
      else if(number==1) {
        return false;
      }
      else if(isNegative(number)){
          isEven(-(number));
      }
      else {
      isEven(number-2);
    }
  
  }
  
  var isNegative = function(n) {
  
    if(n<0) {
        return true;
    }
  
  };
  
  console.log(isEven(50));
  console.log(isEven(75));
  console.log(isEven(-1));
  